3 * - declarations of private objects with external linkage (adns__*)
4 * - definitons of internal macros
5 * - comments regarding library data structures
8 * This file is part of adns, which is Copyright (C) 1997, 1998 Ian Jackson
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software Foundation,
22 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 #ifndef ADNS_INTERNAL_H_INCLUDED
26 #define ADNS_INTERNAL_H_INCLUDED
28 #define PRINTFFORMAT(a,b) __attribute__((format(printf,a,b)))
29 typedef unsigned char byte;
39 /* Configuration and constants */
42 #define UDPMAXRETRIES /*15*/5
43 #define UDPRETRYMS 2000
45 #define LOCALRESOURCEMS 20
48 #define DNS_MAXUDP 512
49 #define DNS_MAXDOMAIN 255
50 #define DNS_HDRSIZE 12
51 #define DNS_CLASS_IN 1
62 /* Shared data structures */
88 adns_status (*parse)(adns_state ads, adns_query qu, int serv,
89 const byte *dgram, int dglen, int cbyte, int max,
91 /* Parse one RR, in dgram of length dglen, starting at cbyte and
92 * extending until at most max.
94 * The RR should be stored at *store_r, of length qu->typei->rrsz.
96 * If there is an overrun which might indicate truncation, it should set
97 * *rdstart to -1; otherwise it may set it to anything else positive.
100 void (*makefinal)(adns_state ads, adns_query qu, void *data);
101 /* Change memory management of *data.
102 * Previously, used alloc_interim, now use alloc_final.
106 typedef struct allocnode {
107 struct allocnode *next;
120 enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
121 adns_query back, next, parent;
122 struct { adns_query head, tail; } children;
123 struct { adns_query back, next; } siblings;
124 struct allocnode *allocations;
126 void *final_allocspace;
128 const typeinfo *typei;
133 /* General-purpose messing-about buffer.
134 * Wherever a `big' interface is crossed, this may be corrupted/changed
135 * unless otherwise specified.
139 /* This is allocated when a query is submitted, to avoid being unable
140 * to relate errors to queries if we run out of memory. During
141 * query processing status, rrs is 0. cname is set if
142 * we found a cname (this corresponds to cname_dgram in the query
143 * structure). type is set from the word go. nrrs and rrs
144 * are set together, when we find how many rrs there are.
148 int cname_dglen, cname_begin;
150 int id, flags, udpretries;
152 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
153 struct timeval timeout;
158 * state Queue child id nextudpserver sentudp failedtcp
160 * udp NONE null >=0 0 zero zero
161 * udp timew null >=0 any nonzero zero
162 * udp NONE null >=0 any nonzero zero
164 * tcpwait timew null >=0 irrelevant zero any
165 * tcpsent timew null >=0 irrelevant zero any
167 * child childw set >=0 irrelevant irrelevant irrelevant
168 * done output null -1 irrelevant irrelevant irrelevant
170 * +------------------------+
171 * START -----> | udp/NONE |
172 * +------------------------+
174 * too big for UDP / UDP timeout \ \ send via UDP
175 * do this ASAP! / more retries \ \ do this ASAP!
177 * +---------------+ +-----------+
178 * | tcpwait/timew | ____ | udp/timew |
179 * +---------------+ \ +-----------+
181 * TCP conn'd; | | TCP died | | |
182 * send via TCP | | more | UDP timeout | |
183 * do this ASAP! | | servers | no more | |
184 * v | to try | retries | |
185 * +---------------+ | desired | |
186 * | tcpsent/timew | ____ | | |
187 * +---------------+ \| | |
188 * \ \ TCP died | TCP | |
189 * \ \ no more | timeout / |
193 * reply \ _| +------------------+ / reply
194 * \ | done/output FAIL | /
195 * \ +------------------+ /
198 * (..... got reply ....)
200 * need child query/ies / \ no child query
203 * +--------------+ +----------------+
204 * | child/childw | ----------------> | done/output OK |
205 * +--------------+ children done +----------------+
210 adns_initflags iflags;
212 struct { adns_query head, tail; } timew, childw, output;
213 int nextid, udpsocket, tcpsocket;
214 vbuf tcpsend, tcprecv;
215 int nservers, tcpserver;
216 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
217 struct timeval tcptimeout;
220 } servers[MAXSERVERS];
225 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
227 /* From general.c: */
229 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
230 int serv, adns_query qu, const char *fmt, va_list al);
232 void adns__debug(adns_state ads, int serv, adns_query qu,
233 const char *fmt, ...) PRINTFFORMAT(4,5);
234 void adns__warn(adns_state ads, int serv, adns_query qu,
235 const char *fmt, ...) PRINTFFORMAT(4,5);
236 void adns__diag(adns_state ads, int serv, adns_query qu,
237 const char *fmt, ...) PRINTFFORMAT(4,5);
239 int adns__vbuf_ensure(vbuf *vb, int want);
240 int adns__vbuf_appendstr(vbuf *vb, const char *data);
241 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
242 /* 1=>success, 0=>realloc failed */
243 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
244 void adns__vbuf_init(vbuf *vb);
245 void adns__vbuf_free(vbuf *vb);
247 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu, vbuf *vb,
248 int flags, const byte *dgram, int dglen, int cbyte);
249 /* Unpicks a domain in a datagram and returns a string suitable for
250 * printing it as. Never fails - if an error occurs, it will
251 * return some kind of string describing the error.
253 * serv may be -1, qu may be 0. vb must have been initialised,
254 * and will be left in an arbitrary consistent state.
256 * Returns either vb->buf, or a pointer to a string literal. Do not modify
257 * vb before using the return value.
260 /* From transmit.c: */
262 adns_status adns__mkquery(adns_state ads, vbuf *vb,
263 const char *owner, int ol, int *id_r,
264 const typeinfo *typei, adns_queryflags flags);
265 /* Assembles a query packet in vb, and returns id at *id_r. */
267 void adns__query_tcp(adns_state ads, adns_query qu, struct timeval now);
268 /* Query must be in state tcpwait/timew; it will be moved to a new state
269 * if possible and no further processing can be done on it for now.
270 * (Resulting state is one of tcpwait/timew (if server not connected),
271 * tcpsent/timew, child/childw or done/output.)
273 * adns__tcp_tryconnect should already have been called - _tcp
274 * will only use an existing connection (if there is one), which it
275 * may break. If the conn list lost then the caller is responsible for any
276 * reestablishment and retry.
279 void adns__query_udp(adns_state ads, adns_query qu, struct timeval now);
280 /* Query must be in state udp/NONE; it will be moved to a new state,
281 * and no further processing can be done on it for now.
282 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
283 * tcpsent/timew, child/childw or done/output.)
288 int adns__internal_submit(adns_state ads, adns_query *query_r,
289 adns_rrtype type, vbuf *qumsg_vb, int id,
290 adns_queryflags flags, struct timeval now,
291 adns_status failstat, const qcontext *ctx);
292 /* Submits a query (for internal use, called during external submits).
294 * The new query is returned in *query_r, or we return adns_s_nomemory.
296 * The query datagram should already have been assembled in qumsg_vb;
297 * the memory for it is _taken over_ by this routine whether it
298 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
300 * If failstat is nonzero then if we are successful in creating the query
301 * it is immediately failed with code failstat (but _submit still succeds).
303 * ctx is copied byte-for-byte into the query.
306 void *adns__alloc_interim(adns_query qu, size_t sz);
307 /* Allocates some memory, and records which query it came from
308 * and how much there was.
310 * If an error occurs in the query, all its memory is simply freed.
312 * If the query succeeds, one large buffer will be made which is
313 * big enough for all these allocations, and then adns__alloc_final
314 * will get memory from this buffer.
316 * _alloc_interim can fail, in which case it will fail the query too,
317 * so nothing more need be done with it.
320 void *adns__alloc_final(adns_query qu, size_t sz);
324 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
325 void adns__makefinal_str(adns_query qu, char **strp);
327 void adns__reset_cnameonly(adns_state ads, adns_query qu);
328 /* Resets all of the memory management stuff etc. to
329 * take account of only the CNAME. Used when we find an error somewhere
330 * and want to just report the error (with perhaps CNAME info), and also
331 * when we're halfway through RRs in a datagram and discover that we
332 * need to retry the query.
335 void adns__query_done(adns_state ads, adns_query qu);
336 void adns__query_fail(adns_state ads, adns_query qu, adns_status stat);
340 void adns__procdgram(adns_state ads, const byte *dgram, int len,
341 int serv, struct timeval now);
345 const typeinfo *adns__findtype(adns_rrtype type);
353 int dglen, max, cbyte, namelen;
354 int *dmend_rlater, *namelen_rlater;
357 void adns__findlabel_start(findlabel_state *fls,
358 adns_state ads, int serv,
359 const byte *dgram, int dglen, int max,
360 int dmbegin, int *dmend_rlater);
361 /* Finds labels in a domain in a datagram.
363 * Call this routine first.
364 * endpoint_rlater may be null.
367 adns_status adns__findlabel_next(findlabel_state *fls,
368 int *lablen_r, int *labstart_r);
369 /* Then, call this one repeatedly.
371 * It will return adns_s_ok if all is well, and tell you the length
372 * and start of successive labels. labstart_r may be null, but
373 * lablen_r must not be.
375 * After the last label, it will return with *lablen_r zero.
376 * Do not then call it again; instead, just throw away the findlabel_state.
378 * *dmend_rlater will have been set to point to the next part of
379 * the datagram after the label (or after the uncompressed part,
380 * if compression was used). *namelen_rlater will have been set
381 * to the length of the domain name (total length of labels plus
382 * 1 for each intervening dot).
384 * If the datagram appears to be truncated, *lablen_r will be -1.
385 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
386 * Do not call _next again.
388 * There may also be errors, in which case *dmend_rlater,
389 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
390 * Do not then call findlabel_next again.
393 adns_status adns__parse_domain(adns_state ads, int serv, vbuf *vb,
394 const byte *dgram, int dglen,
395 int *cbyte_io, int max);
396 /* vb must already have been initialised; it will be reset if necessary.
397 * If there is truncation, vb->used will be set to 0; otherwise
398 * (if there is no error) vb will be null-terminated.
399 * If there is an error vb and *cbyte_io may be left indeterminate.
402 adns_status adns__findrr(adns_state ads, int serv,
403 const byte *dgram, int dglen, int *cbyte_io,
404 int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
405 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
407 /* Finds the extent and some of the contents of an RR in a datagram
408 * and does some checks. The datagram is *dgram, length dglen, and
409 * the RR starts at *cbyte_io (which is updated afterwards to point
410 * to the end of the RR).
412 * The type, class and RRdata length and start are returned iff
413 * the corresponding pointer variables are not null. type_r and
414 * class_r may not be null.
416 * If the caller thinks they know what the owner of the RR ought to
417 * be they can pass in details in eo_*: this is another (or perhaps
418 * the same datagram), and a pointer to where the putative owner
419 * starts in that datagram. In this case *eo_matched_r will be set
420 * to 1 if the datagram matched or 0 if it did not. Either
421 * both eo_dgram and eo_matched_r must both be non-null, or they
422 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
423 * The eo datagram and contained owner domain MUST be valid and
426 * If there is truncation then *type_r will be set to -1 and
427 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
430 * If an error is returned then *type_r will be undefined too.
433 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
437 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
438 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
440 void adns__autosys(adns_state ads, struct timeval now);
441 /* Make all the system calls we want to if the application wants us to. */
443 /* Useful static inline functions: */
445 static inline void timevaladd(struct timeval *tv_io, long ms) {
449 tmp.tv_usec += (ms%1000)*1000000;
450 tmp.tv_sec += ms/1000;
451 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
455 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
456 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
457 static inline int ctype_alpha(int c) {
458 return (c >= 'a' && c <= 'z') || (c >= 'A' || c <= 'Z');
463 #define MEM_ROUND(sz) \
464 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
465 * sizeof(union maxalign) )
467 #define LIST_INIT(list) ((list).head= (list).tail= 0)
469 #define LIST_UNLINK_PART(list,node,part) \
471 if ((node)->back) (node)->back->part next= (node)->part next; \
472 else (list).head= (node)->part next; \
473 if ((node)->next) (node)->next->part back= (node)->part back; \
474 else (list).tail= (node)->part back; \
477 #define LIST_LINK_TAIL_PART(list,node,part) \
479 (node)->part back= 0; \
480 (node)->part next= (list).tail; \
481 if ((list).tail) (list).tail->part back= (node); else (list).part head= (node); \
482 (list).tail= (node); \
485 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
486 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
488 #define GETIL_B(cb) (dgram[(cb)++])
489 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
490 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))